I got my first 3D printer when my wife, Kim, suggested that I should get one. It’s not like I hadn’t been talking about the idea for a few years, but she pushed me over the edge. I’ve stayed grateful for this gentle nudge!
I return the favor by designing and printing objects that help her with her passion: Passing on her love of mathematics (she’s a math PhD) to middle and high school students. She does this directly by teaching and tutoring students, and indirectly by running the local chapter of Math Teachers’ Circles, the beautifully-named Triangle Math Teachers’ Circle. She has a bin full of things I’ve printed, and as she gives them away to people who are reluctant to give them back, I print more. 
Today, she excitedly told me about a web site where people are developing a geometry curriculum for blind and visually impaired learners — which should also be useful for normally-sighted people.
I followed the github link, and — wow, @Whosa_whatsis, nice work you’ve been doing! The geometry class that Kim was scheduled to teach this fall has been COVID-cancelled and the Math Teachers’ Circles are currently online, but I see a lot more geometric printing in my near future.